Recalcitrant compounds

Nitrobenzene originates from numerous industrial and agricultural activities, and can be abiotically removed at a cathode coupled to microbial oxidation of acetate at an anode, as shown by Mu et al. [140]. Finally, a model antibiotic (ceftriaxone) was shown to be oxidatively removed and to boost current production from glucose in the anode in an air-cathode MFC [137]. 

The chlorinated solvent 1,2-dichloroethane was removed in the anode of an M FC without the production of any toxic intermediate at a maximum removal rate of 40gm anode surface day [173]. Biogenic palladium nanoparticles produced by the precipitation of Pd on the surface of bacteria have been used as a catalyst for the dehalogenation of trichloroethylene and diatrizoate in the cathode of an MEC [25]. 

Root residues (mainly organic compounds) from rice plants produce methane. It is estimated that worldwide rice agriculture contributes 7-20% of the total 

Uranium and mercury have also been removed using BBSs. Lovley and co-workers demonstrated that Geohacter suljurreducens can use electrons derived from electrodes to reduce U(VI) to the less soluble U(IV), and that it may be possible to remove and recover uranium with poised electrodes [175, 176). Power generation (433.1 mW m ) coupled with mercury removal (240 mg Hg 1 day, 99% removal efficiency in batch) in the cathode of an MFC was shown to be possible. Mercury was recovered as elemental Hg (on the cathode surface) and Hg2Cl2 (deposited on the bottom of the chamber) [177]. 

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CometaboHsm refers to situations where a compound caimot be biodegraded effectively unless another food source is available. The recalcitrant compound, such as TCE, does not provide the energy to allow the microorganisms to grow and thrive. When another food source is available such as... 

The presence of glucose may suppress degradation of a recalcitrant compound ... 

The presence of glucose may, however, enhance the degradation of a recalcitrant compound. Several different metabolic situations may be discerned, each probably representing a different mechanism for the stimulation ... 

Cook AM, R Hiitter (1981) Degradation of 5-triazines a critical view of biodegradation. In Microbial Degradation of Xenobiotics and Recalcitrant Compounds (Eds T Leisinger, AM Cook, R Hiitter, J Niiesch), pp. 237-249. Academic Press, London. 

Neilson AH, A-S Allard, M Remberger (1985) Biodegradation and transformation of recalcitrant compounds. Handb Environ Chem 2C 29-86. 

As wastewater from resin-producing factories contains recalcitrant compounds, the removal efficiencies achieved by means of the nitrification-denitrification systems could not reach the required disposal values and a posttreatment, such as ozonation, would be necessary to enhance the biodegradability of those compounds.2 53... 

Deeb, R.A. and Kavanaugh, M., In-Situ biological destruction of MTBE Field engineering solutions, Remediation of Chlorinated and Recalcitrant Compounds Conference, Monterey, CA, May 23, 2002. 

Chang, H.L. and Yen, T.F., An improved chemical-assisted ultrasound treatment for MTBE, Proceedings of the Second International Conference on Remediation of Chlorinated and Recalcitrant Compounds, Battelle Press, Columbus, OH, 2000. 

Landmeyer, J.E., Vrblosky, D.A., and Bradley, P.M., MTBE and BTEX in trees above contaminated groundwater, Battelle International Conference on Remediation of Chlorinated and Recalcitrant Compounds, Monterey, CA, 2000. 

Because of UV filters are substances designed to absorb solar energy, photolysis and photocatalysis have been tested as a feasible treatment to degrade the recalcitrant compounds. To date, very few studies have examined UV filters response under UV radiation when exposed in aqueous samples [41-44], Results indicate that the extent of degradation is quite variable, from no photodegradation of BP3 to complete mineralization of BP1 after 24 h of UV light irradiation. 

Kulla HG (1981) Aerobic bacterial degradation of azo dyes. In Leisinger T, Cook AM, Niiesch J, Hiitter R (eds) Microbial degradation of xenobiotics and recalcitrant compounds. Academic, London, pp 387-399... 

Single, slug-type release contaminant degrades to more recalcitrant compound... 

Meinardus, H. W., Jackson, R. E., Jin, M., Londergan, J. T., Taffinder, S., and Ginn, J. S., 1998, Characterization of a DNAPL Zone with Partitioning Interwell Tracer Tests In Nonaqueous-Phase Liquids, Remediation of Chlorinated and Recalcitrant Compounds (edited by G. B. Wickramanayake and E. Hinchee), Battelle Press, Columbus, OH, pp. 143-148. 

Wickramanayake, G. B. and Hinchee, R. E. (editors), 1998, Nonaqueous-Phase Liquids — Remediation of Chlorinated and Recalcitrant Compounds Battelle Press, Columbus, OH, 255 pp. 

Fewson, C.A. Biodegradation of aromatics with industrial relevance, in FEMS Symp. No. 12. Microbial Degradation of Xenobiotics and Recalcitrant Compounds, 12 141-179,1981. 

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